trane conderser unit not starting
Posted 18 June 2006 - 08:25 PM
so i know the comp and cond fan and cap are ok
i checked the thermostat wire and i do have continuety
thru the wire i cant seem to measure 24 volts to the unit
this may be due to using a 15 year old analog meter im useing
on 2nd thought it wouldnt cause jumped the contactor
wires to the tstat still nothing my question is theres a
transfomer in the blower unit im guessing thats stepping the 110 to 24 volts to send to the cond unit the also a
main control board on the blower unit in the apt
which i think is my problem but not sure how to check it
as a side note i have 2 units side by side neither
started this year im trying to get this one going first
its gooing to the top floor which is pretty hot
this is a trane m/n for cond unit is ttro42c1ooa1
s/n is h22273646 the air handler m/n is tud12oc96a01
the main control board in the air handler #is 50a50-405
which i think subs to cnt03797 sorry for the long post but wanted to get the nessary info in any help appreciated
i think im going to buy the board and transformer this unit does it sound like im on the right track?
Posted 19 June 2006 - 04:20 PM
Posted 19 June 2006 - 07:50 PM
on low presure or anything your right about the tstat connections only difference my tstat wires are brown and white my main question is will the control board keep the condensing from starting if so can i jump it out also do uknow if the transformer in the blower unit is to send 24 volts to the cond unit im not geting low voltage to the contactor from the blower unit im an appliance tech myself
so im determinded to fix this myself and learn more about central air systems thanks for the help
Posted 24 June 2006 - 11:18 AM
Whoa, Slow down there buck-a-roo. In order to become a good trouble shooter U have to start with the simple stuff 1st
Do U have main power to both the furnace and condenser sections. If yes then carefully remove the thermostat from its subbase to expose the wires. On the subbase U will C terminals marked "R, Y, W,G". Set UR meter to A/C volts and put 1 probe on R and the other on G. Do U have 24 VAC? Check R to the other terminals. U should have 24 VAC between R and the others.
If U have it read on. If not then most likely the step down transformer in the furnace section has burnt out. Watch thou. Some times the transformers are protected by a fuse and it could just B the fuse thats bad. Be carefull. Always folllow caution when dealing with electricity.
If U have24 VAC at the stat do this. Put the stat back on. Turn main power off to the condenser section and take off the panels to expose the contactor, capacitor, etc. You will C 2 wires going to the coil of the compressor contactor. Not !!! the main power wires. The 2 wires U want are the smaller ones. Take one of the wires off the contactor and make sure it dosen't touch anything.
Go inside and make UR thermostat call for cooling. Make sure the fan starts. Now go back to the condenser. With UR meter still set to VAC and main power still off, put one probe on the wire still connected to the contactor and touch the other probe to the wire U took off. Have 24VAC?? If yes then the contactor is bad and thats why the condenser section isn't running.
If no then U could have a defective stat or a break in the wires going out to the condenser, or as Jedi said, are we sure were looking at the right machine, since U have 2 side by side.
Hope this helps:)
Posted 19 July 2006 - 06:34 AM
respliced and connected problem solved
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